Ladders are commonly used for climbing up or down from one given level to another. Their most typical construction consists essentially of two long vertically oriented runners, known as side rails, separated and joined at intervals by cross pieces, known as rungs, on which to step. The origin of the word ladder comes from the old English word hlinian which simply means to lean. This obviously relates to the fact that ladders are commonly leaned on a wall or the like. In terms of physics, the angle of this lean, or angle of inclination, translates a portion of the vertical force, resulting from the combined weight of the ladder and user, into a horizontal component which tends to push the bottom of the ladder away from the wall. If this force is not balanced by an opposite force, typically friction, then the ladder will slide out from the wall against which it is leaning. It is obvious why this event must be avoided.
It is known in the prior art to add ladder shoes to the ends of a ladder's rails to increase traction. It is common to construct ladder shoes such that they can pivot, slide or rotate about the ends of the rail into two positions. The first position typically engages the ladder shoe flat against a surface. The second position typically engages the ladder shoe such that a spur plate of the shoe is aligned in parallel with its side rail so that it can engage with a penetrable surface such as grass and securely maintain the ladder thereon. In the past, it has been an inefficient ordeal to hold the ladder off of the ground while trying to move and hold the ladder such that the spur plate is disposed to properly penetrate into grass or the like.
Applicant's invention overcomes this problem by providing a ladder shoe that can be easily positioned and maintained in an intermediate position such that as the ladder is lowered into engagement with the ground, the ladder shoe is naturally urged into the second position. If it is desired to disengage the ladder shoe from the intermediate position, the ladder shoe need only be nudged.